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Record W1592038284

Carbon dioxide and methane exchange in a boreal wetland

2000· article· en· W1592038284 on OpenAlexaboutno aff
Andrew E. Suyker

Bibliographic record

VenueLincoln (University of Nebraska) · 2000
Typearticle
Languageen
FieldEnvironmental Science
TopicPeatlands and Wetlands Ecology
Canadian institutionsnot available
Fundersnot available
KeywordsCarbon dioxideMethaneWetlandBorealEnvironmental scienceCarbon cycleEcologyEcosystemBiology
DOInot available

Abstract

fetched live from OpenAlex

Detailed information on carbon exchange in northern wetlands is needed to improve our understanding of global carbon cycle and predictions of future climatic conditions. For this reason, fluxes of carbon dioxide and methane were measured in a boreal wetland in central Saskatchewan as part of the Boreal Ecosystem Atmosphere Study (BOREAS) in 1994 and 1995. Seasonal patterns of midday CO2 flux were comparable in the two years. Peak midday CO 2 uptake (about 0.5 to 0.6 mg m−2 (ground area) s−1) occurred in early July concurrent with peak LAI (≈1.3). The relationship between CO2 flux (normalized by leaf area) and incident photosynthetically active radiation was similar in both years. High vapor pressure deficit (1.5 < D < 3.2 kPa) and air temperature (20 < Ta < 30°C) reduced CO2 flux significantly. Integrated net ecosystem CO2 uptake was 89 and 108 g CO2-C m−2 (890 and 1080 kg CO2-C ha−1 ) in the 1994 and 1995 growing seasons, respectively. Periods of high vapor pressure deficit and air temperature, a brief interval of cloudy/cool conditions, and a brief temporary rise of the water table in 1994 were likely associated with the lower carbon uptake. Seasonal trends of methane emission showed some similarities in the two years. Maximum seasonal methane emission was of comparable magnitude (19.5 and 16.5 mg m−2 h−1 in 1994 and 1995, respectively) and occurred about the same time as the highest peat temperatures and water tables. However, peak methane emission occurred much earlier (5 to 6 weeks) in 1995: this was probably linked to the contrasting seasonal trends of peat temperature and water table between years. Peat temperature and water table also reached their peak values later in the 1994 season. Sensitivity of methane emission to changes in peat temperature and water table was consistent between the two seasons. Seasonally integrated methane emission of 16.3 and 17.9 g CH4-C m−2 (163 and 179 kg CH4 -C ha−1) in 1994 and 1995 respectively, was 15–20% of the net ecosystem CO2 exchange. Thus, for a productive wetland as studied here, carbon loss through methane emission is significant in the overall carbon budget.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

How this classification was reachedexpand

Full frame machine prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: Observational
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.061
Threshold uncertainty score0.122

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.007
GPT teacher head0.183
Teacher spread0.177 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designObservational
Domainnot available
GenreEmpirical

How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".

Quick stats

Citations0
Published2000
Admission routes1
Has abstractyes

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